Oil burner system



Nov. 25, 1941. l.. l. ALDRICH OIL BURNER SYSTEM Filed Feb. 2, 1959 3 Shee'ts-SheefI l .mw Nw INVENTOR.

I Qfz'c/a SV ATTORNEYS ey W16@ 3 5 Sheets-Sheet 2 ATTORNEYS.

Nov, 25, 1941.

Filed Feb. 2, 1959 Nov. 25, 1941. ALDRICH OIL BURNER SYSTEM Filed Feb. 2, 1939 3 Sheets-Sheet 5 BY yC-Jaarw @MJ ym ATTORNEYS.

Patented Nov. 25, 1941 UNITED STATES 'PATENT OFFICE OIL BURNER SYSTEM Loyd I. Aldrich, Peoria, Ill.

Application February 2, 1939, Serial No. 254,197

6 Claims.

An object of my present invention is to provide an oil burner system particularly adapted for efficiently burning heavy gravity fuel oil such as commonly known on the market as No. 4 or No. 5 oil.

A further object is to provide a system including apparatus which utilizes a high pressure nozzle of the conventional oil burner and conditions the oil so that it can be eihciently atomized thereby in the same manner that low viscosity oil is at the present time utilized in such burners.

More particularly it is my object to preheat heavy fuel oil to a temperature adjacent the ash point thereof so that its Viscosity comes in the neighborhood of ordinary light oils now lused for conventional high pressure burners.

Another object is to not only preheat the oil itself but preheat the nozzle and at the same time withdraw congealed oil from the supply pipe leading to the nozzle when the burner is started, such congealed oil being a result of intermittent operation of the burner by which the nozzle and the various pipe lines become cooled 01T after the burner stops operating and thus causes congealment of the oil therein.

Still another object is to provide an oil burner system in which a fuel pump operates at substantially full capacity and circulates substantially more oil than is required by the nozzle, thus insuring that the nozzle and all parts of the system between the nozzle and oil preheater are maintained at the desired temperature to keep the oil in its passage from the preheater to the nozzle at the desired viscosity for eiiicient atomization at the nozzle.

Another object is to provide a special nozzle mechanism which constitutes an adapter so that a standard nozzle tip can be used in connection with the nozzle mechanism and burn oil that is heavy at ordinary temperatures with the same degree or a greater degree of eilciency than light cold oils are now burned, the nozzle mechanism including a needle valve normally closed for preventing any dripping of oil at the nozzle tip and the parts being so constructed that the needle valve is opened after the oil pump starts to operate and thereafter remains open to such -a degree that the desired oil pressure at the burner is maintained regardless of the higher pressure produced by the oil pump.

Still another object is to provide control means which eiects maintenance of the oil in the preheater at a substantially constant uniform temperature, there being provided -a control switch responsive to the temperature of the oil in the preheater for preventing operation of the oil pump until the oil in the preheater has attained a predetermined temperature satisfactory for operation according to my system.

Still a further object is to provide control means to permit oil to bypass through the nozzle supporting mechanism and return to the preheater by Way of an auxiliary return line until the nozzle mechanism has been sufficiently heated by circulating preheated oil that is in condition for ejection of preheated oil for burning purposes, such control means being preferably timed to permit a predetermined period for circulation of the cil through the auxiliary return line.

Still a further object is to provide in the preheater a strainer for the incoming oil, such strainer being in the zone of heat of the heating means in the preheater so that it is always kept hot and thereby causes the incoming oil to be immediately heated so that its consistency is thin to a point where it can pass through a very iine screen and thus impurities in the oil may be efciently removed therefrom, even though the oil is initially so heavy that straining thereof to the desired fineness is prohibitive.

With these and other objects in View my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings. Although the invention is susceptible of a variety of embodiments, it is unnecessary to fully describe and illustrate more than one in order to give a full understanding of the invention both from its structural and functional standpoints. Accordingly, I have illustrated a preferred and desirable embodiment of the invention in the accompanying drawings, in which:

Figure 1 is a plan view of an oil burner system embodying my invention.

Figure 2 is an enlarged sectional view thereof in which the upper portion is taken on the line 2-2 of Figure l and the lower portion thereof is taken on the line 2a-2a of Figure 1, the parts being diagrammatically associated with each other to illustrate their cooperative relationship. Figure 2a is a detail plan View as on the indicated line Zat-2a of Figure 2.

Figure 3 is a more greatly enlarged sectional View on the line 3 3 of Figure l and showing particularly the nozzle mechanism 0f my oil burning system. Figure 3a is a detail sectional View on the line 3ft-3a of Figure 3.

Figure 4 is a sectional view on the line 4-4 of Figure 2 showing details of construction in the preheater of my oil burning system.

Figure 5 is a diagrammatic view partially electrical showing my system and the controlling circuits therefor, and

Figure 6 is a similar diagrammatic view of a modied form of preheater.

On the accompanying drawings I have used the reference character B to indicate generally the burner mechanism,y P a preheater and T an oil supply tank. The burner B is of substantially conventional type with the exception of the internal structure shown in detail in Figures 2 and 3 which will hereinafter be described. In general it includes an electric motor Ill secured to a blower housing I2 in which is mounted a blower I3 for furnishing air to the blast tube I4. The type of burner shown .is usually designated as a gun type.

Anl oil pump I5 is mounted on an air intake housing IT of the blower B and driven from the shaft VIii of the motor IU.

Within the blast tube I4 I provide nozzle mechanism including a body N formed of a casting or the like and having an adapter nut I9 mounted at the discharge 'end thereof. A conventional nozzle tip 2i! is screwed into the adapter nut I9 and has the usual discharge orifice 2l. Nozzles of this character are usually provided with a partition wall 22 having a plurality of spirally arranged openings 23 adapted to 'give the oil passing therethrough a rotary motion before it is discharged from the o'rice 2|.

The body N has an intake passageway 24, a return passageway 25 and an auxiliary return passageway 25. vConnected with the passageway 24 is a supply pipe 21 lextending from the voutlet 28 of the pump I8. A return pipe '29 is connected with the return passageway 25 and on its outer end has a four-way fitting 39. The tting 3l! is arranged against a panel 3'I which in turn is arranged against the back of the blower casing `I2 'with a gasket 32 between the casing and the panel.

Within the body N I provide a bore 33 aligned with the adapter nut I9 and with a needle valve opening 34 therein. A needle valve -35 is adapted to cooperate with the opening 34 and I'normally retain the needle valve seated under constraint of a spring 3B.

The spring -36 is interposed between a piston 8'! in the bore 35 and an adjusting disc 33. The adiusting-disc 38 is threadedly mounted in the return passageway 25.

For effecting adjustment of the spring 35 the disc 38 may be rotated. An adjusting rod 39 is provided for this purpose. It is pinned at 4l) to a sleeve-like extension Aof the Vdisc 33 and vextends into a sleeve 4I which in turn is mounted in the four-way fitting 3i). A cap nut 42 normally encloses the outer end of 'the adjusting rod 39 and may be removed for permitting insertion of a screw-driver in a slot 43 of the rod for eifectin'g adjustment of the spring 36.

Loosely surrounding the needle valve 35 is a sleeve-like cage 44 having a ne mesh tubular screen 45 supported thereon. A spring 46 is interposed between the cage 44 and the piston 3'! to retain the cage assembled in position in a socket 41 of the adapter nut I9.

The bore 33 is provided with an annular enlargement 48 communicating with ports 49. The parts are so related that after the needle valve 35 is unseated, the piston 3l will register with the annular enlargement 48 and permit passage of oil around the piston when the parts are in the position of Figure 3a, such oil then passing through the ports 39 to the space in the body N in which the spring 35 is mounted.

The oil flows around the valve stem 35 and spring 45 and then laterally through openings 5i] in the piston 49 before entering the annular enlargement 48. After leaving the ports 49 the oil iiows through the bore of the sleeve-like disc 38 and laterally through .periorations 5I thereof.

The preheater P of my system includes an oil container C consisting of a cylindrical wall 52 and end walls 53 and 54. The walls 54 and 54 are retained in position by tie rods 55 with suitable gaskets interposed between the heads and the cylinder 52. (See Figure 4.) The heads 53 and 54 are provided with extensions 55 and an outer cylindrical casing 51 surrounds the oil container C and engages the extensions. Supporting brackets 58 vare provided for supporting the preheat'er P relative to a floor surface or the like. The outer casing 5l has end plates 59 and between the out-er casing and the oil container C heat insulating material 60 is provided to prevent dissipation of heat from the container C and thereby cause operation of the structure of the preheater at maximum efficiency.

The head 54 is .provided with a bore 5I adapted to receive a strainer S including a sleeve-like element 52 received in the bore 5I. The bore 6I has an enlarged annular groove E53 adapted to receive oil from a supply pipe 64 which is preferably fed by gravity from the tank T. The element 62 terminates in a ange 62a secured to the head 54 by cap screws or the like B2b with a suitable gasket Ainterposed between the head and the flange.

The element 52 is provided with a plurality of openings B5 through which the oil flows to the interior of a tubular screen S5. The inner end of the screen is closed by a plug 61.

The head 53 is provided with a bore 68 adapted to receive a heating unit H. The unit I-I is preferably of electrical type including a resistance element B9 (see Figure 4) encased in a metal sheath 19. The sheath 'I0 is secured to a hub I2 which terminates in a ange 'I3 adapted to be secured to the head 53 by cap screws or the like 'I4 with a suitable gasket interposed between the flange and the head. A terminal support 'I5 has terminals 15 for the heating element 69.

Communicating with the bore 68 is an outlet pipe 'I'I extending to the pump I5. It will be noted that the hub 12 is of such size relative to the bore 68 that oil 'from the container C must pass over the heater H upon leaving the container and flowing to the pump I6. Connected with the top of the cylinder 52 is a pipe 29a which in turn is connected by a conduit 29h, preferably of copper tubing, to the return pipe 29. A vent pipe 'I8 extends from the cylinder 52 preferably back to the tcp of the tank T so that any air trapped in the preheater P may be allowed to escape.

Within the container C are a pair of capillary bulbs 79 'and 8D (see Figure 5) connected by capillary tubes 19a and 80a to control switches S2 and S1. The switch S2 is connected in series across the line with the heater H by wires a, l) and c, the line wires being indicated as L and L. The switch S1 is connected in yseries with the pump motor Ill and with any suitable control switch such as a room thermostat RT. Wires d, d' and e are provided for this purpose.

Connected with the auxiliary return passageway 26 is a conduit 8| leading to a solenoid valve SV. From the Valve a line 82 leads to the fourway fitting 30 so that when the valve is open and oil is being supplied from the pipe 21, the oil can flow through the solenoid valve and return by way of the pipes 29h and 29a. The solenoid valve SV includes an electric winding 83 in series with the room thermostat RT and with a timer switch TS in series in this circuit.

The wires of the circuit are indicated at 9, h and z'. The timer switch TS includes a bimetal element 84 normally engaged with a contact 85. When heated to a predetermined degree, the bi-metal element 84 warps away from the contact element 85. For thus warping the element I provide a heating element 86 connected with the wire f and by a wire y' to the wire c.

In Figure 6 I show a modified form of the invention in which a second heater H is located within the strainer S and is connected in parallel with the heater H by wires b and c.

It will be noted in Figure that the strainer S is located directly over the heater H so as to be in the zone of heat therefrom While the heater I-I in Figure 6 serves as an even more eiective means to insure preheating of the incoming oil.

Practical operation In the operation of my oil burner system, when current is rst supplied to the line wires L and L and providing the room thermostat RT is closed the switch S2 will be closed due to the container C being at substantially room temperature. No. 4 or No. 5 oil is extremely heavy and at room temperature cannot be passed through a fine screen nor can it be properly atomized nor pumped through small copper tubes with any degree of assurance that it will flow uniformly. I accordingly have the switch S2 set for operation at a relatively high temperature (190 or 200) I have found that this is satisfactory for an oil that has a flash point of 235 as it reduces the oil to the desired viscosity for efficient atomization at the nozzle tip and the consistency of the oil is then such that it will pass through a Very ne screen (120 mesh). Such a screen will effectively strain out all impurities and will require cleaning out not more than once or twice a season, with the usual run of oil.

When the heater H brings the temperature Of the oil in the container C up' to the point where the switch S2 cuts out, there will be discontinuance of the heat in the heater H and the switch S2 will thereafter operate to maintain the temperature of the oil in the preheater substantially constant, cutting in when the temperature recedes below the setting of the switch and cutting out when it exceeds that temperature at which the switch is set.

When the temperature of the oil gets up to about 175 the switch S will cut in so that the motor I8 can operate as the oil is now suiiiciently hot for atomization. The circuit is established from wire d to wire d' by the closing of the switch S1 and this circuit in addition to energizing the motor I8, energizes the heater 86 of the timer switch TS by current passing through the switch S1. Also the solenoid coil 83 is energized by current passing through g, h and i and through the timer contacts 84 and 85. This will cause the solenoid valve SV to open so that the oil pumped by the pump I6 merely iiows into the passageway 24 of the nozzle body N and out of the passageway 26. From the passageway 26 it flows through pipe 8l, the solenoid valve SV and pipe 82, iitting 38 and pipes 29h and 29a, returning to the container C.

During the timing period of the timer switch ST, this preheated oil will continue to flow, thus thoroughly heating the entire pipe system and the nozzle body N and removing all congealed oil from the nozzle body.

After the timing period of the switch TS has been completed (30 or 40 seconds is sufficient), then the circuit through wires g, h and i is broken at the contacts 84 and 85 so that the solenoid coil 83 is deenergized. This permits the valve SV to close and it is maintained closed by the pressure of the oil in the pipe 8|.

Thereupon the oil pressure is built up within the nozzle body N and acts upon the piston 31 against the constraint of the spring 36 to move the piston back to the position of Figure 3a. In moving to this position the needle valve 35 is unseated from the opening 34 whereupon the preheated oil now circulating through the nozzle body N is discharged from the nozzle tip 28. Since it is thoroughly preheated oil, its consistency or viscosity is such that it is eiectively atomized and flows freely through the spirally arranged openings 23 so as to give the desired whirling motion to the spray as it burns. I have not shown any ignition system for the oil as the usual electrode type is used and forms no part of my present invention.

When the piston 3'! reaches the position shown in Figure 3a, oil in excess of that required by the nozzle tip 2l] bypasses the passageway 48 and 49 and returns through the pipe 29, etc. to the container C as already described. The pressure of the spring 36 against the piston 31 effects an automatic pressure regulation in the usual manner of relief valves so that the spring 36 can be adjusted to secure diliferent pressures for various nozzles or cil flow from a given nozzle. The strainer screen 45 prevents any possibility of dirt that might have been in the piping getting into the nozzle tip 20 and is in the path of circulated preheated oil so that it likewise may be a very fine screen yet efcient straining of initially heavy oil thinned down by preheating is eiected.

Whenever the room thermostat R'I opens, the motor I8 and the heater 86 are deenergized so that the pump I6 stops operating and the pressure of the oil is allowed to recede. The spring 36 thereupon promptly closes the needle valve 35 so there is no dripping of oil at the nozzle tip and hence the formation of carbon is reduced to the absolute minimum.

The -switch S1 insures that there can be no operation of the pump I6 except when the oil is sufiiciently preheated to accomplish its purpose of initial circulation to warm up the pipe system and the nozzle body before the solenoid valve is closed and the oil thereupon sprayed from the nozzle tip.

I am aware that heretofore oil has been preheated prior to being atomized and burned. I, however, circulate a greater amount of hot oil through the nozzle, than is consumed by the nozzle so that all parts of the oil pipe system are kept hot. This excess oil circulation and the initial bypassing of hot oil through the nozzle before it is sprayed from the nozzle tip are features of my invention which I believe are novel. Also, the heating of the oil so that it can be strained through a fine screen contributes materially to the effective operation of an oil burner of the kind herein disclosed on high gravity oil.' Recently there has been a movement toward the removing of lighter grades of oil from the market as a fuel for oil burners as these lighter grades can be cracked for gasoline. My system makes possible the use of very heavy cil of the character that is unsuitable for cracking processes and utilizes an eiective preheating of the oil and a subsequent utilization of the preheated oil in such manner that nothing but thin Viscosity oil is sprayed from the nozzle, thus increasing the eiciency of combustion andY diminishing 'the possibility of the formation of carbon. Furthermore, by conditioning the oil so that it can be finely atomized at relatively high pressures (100 or 175 pounds per square inch), I am able to secureV greater heating from a given quantity of oil as heavy gravity oil is capable of delivering more B. t. u.s than lighter oils.

My nozzle structure shown in Figure 3 is so designed as to make possible the operation of the system disclosed and the utilization of standard nozzle tips Which are designed for relatively lighter oils.

Some changes may be made in the construction and arrangement of the parts of my oil burner system Without departing from the real spirit and purpose of my invention, and it is my intention to Vcover by my claims any modied forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

I claim as my invention:

1. In an oil burner system, an oil preheater, a nozzle, electric means for pumping more oil from said preheater to said nozzle than required for operation of the nozzle, means for maintaining oil in the preheater at a substantially constant predetermined temperature, means responsive to the temperature of the oil within the preheater to prevent operation of said pump means until said oil in the preheater attains a predeterminedl temperature, and electric timing means operable from the circuit of said pump means, upon such circuit being established, to bypass oil from said nozzle to said preheater to remove congealed oil from the nozzle and heat the nozzle by passage of the preheated oil therethrough during the timing period of said timing means, said timing means at the expiration of the timing period, closing the bypass while permitting said pump means t0 continue to operate.

2. In an oil burner system, an oil preheater, a nozzle, means ior pumping more oil from said preheater to said nozzle than required for operation of the nozzle, means for maintaining oil in the preheater at a substantially constant predetermined temperature, means responsive to the temperature of the oil within the preheater to prevent operation of said pump means until said oil in the preheater attains a predetermined temperature and timing means operable by initiation of the operation of said pump means to bypass oil from said nozzle to said preheater to remove congealed oil from the nozzle and heat the nozzle `by passage of the preheated oil therethrough constant predetermined temperature and timing means operable by initiation of the operation of said pump means and during the timing period of said timing means to bypass oil from a point adjacent said nozzle to said preheater and prevent discharge of oil from the nozzle, said pumping means, after expiration of the timing period, continuing to operate independent of t -e timing means.

4. In an oil burner, an oil preheater, a tank for supplying oil to said preheatena nozzle body, an electric pump for pumping oil from said preheater and supplying it to said nozzle body, a nozzle through which oil is discharged from said nozzle body, the capacity of said pump being in excess of the requirements of said nozzle, a return line for removing congealed oil from'said nozzle body at said nozzle and returning it to said preheater, a normally closed closure means for said nozzle, means operable by building up of oil pressure in saidnozzle body to open said closure means and thereafter maintain the oil pressure to the nozzle substantially uniform at a predetermined pressure, and means for preventing the building up of such pressure for a time period after said pump starts operating, said last means including a passageway leading from said nozzle to said preheater, a valve in said passageway, electrically operated means for opening said valve, the circuit energizing said pump also energizing said electrically operated means, and electric timing means also operated from said circuit for deenergizing said electrically operated means.

5. An oil burner system comprising an oil preheater, nozzle mechanism including a normally closed Valve, oil pressure operated means for opening said valveiwhen the oil pressure in the nozzle mechanism reaches a predetermined degree, electric means for pumping oil from said preheater to said nozzle mechanism, a normally closed return line andan auxiliary return line from said nozzle mechanism to said preheater, a normally closed electrically opened valve connected in the circuit of said electric oil pumping yupon the expiration of a time period following the starting of the oil pumping means, oil pressure operated means for establishing communication from said nozzle mechanism to said first return line when oil in the nozzle mechanism reaches a predetermined degree after said valve is closed, said oil pressure operated means eiTecting pressure regulation of the oil in said nozzle mechanism after said lrst return line is opened.

6. In an oil burner system, a nozzle mechanism including a body having supply and return lines connected therewith, means for supplying heated oil to said supply line, a nozzle tip associated with said nozzle mechanism, a valve normally closed and positioned between said nozzle mechanism and said nozzle tip, pressure operated means subjected to the pressure of the oil from said supply line, resilient means cooperating with said pressure operated means to counteract the oil pressure acting thereagainst and thereby normally retain said valve closed, means to bypass oil from said nozzle tip upon movement of said pressure operated means in response to a Dredetermined pressure being built up by the oil from said supply line in said body and return the by-passed oil to said return line, an auxiliary return line connected with said body at said nozzie tip, a valve normally closed and operable to open said auxiliary return line when oil is initially supplied from said supply line and close it after a quantity of preheated oil has passed from said supply line t0 said auxiliary return line, said Valve being operated to Open position simultaneously with operation of said means for supplying oil, and timing means to stop operation of said valve to permit it to close a time period after said means for supplying oil starts operating and While said means for supplying oil continues to operate.

LOYD I. ALDRICH 

